Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds value beyond these by disclosing the output contents (description, license, update frequency, tags, downloadable resources with formats and URLs) and the external source (dados.gov.pt), which matters because there is no output schema. It does not cover rate limits or errors, but that is less critical for a simple fetch.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One sentence that front-loads the action and resource, then compacts the returned fields into a readable list. Every part earns its place, with no filler or tautological restatement of the title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a one-parameter, read-only lookup with rich annotations and no output schema, so the description's inclusion of expected return contents makes it functionally complete. An agent can call it correctly with only the id or slug, which is all the tool needs.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The sole parameter is already documented in the schema at 100% coverage as 'Dataset id or slug.' The description repeats this phrase without adding format, syntax, or value constraints, so it provides no additional semantic value beyond the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Fetch'), a specific resource ('a single dataset from dados.gov.pt'), and the retrieval key ('id or slug'). The word 'single' helps distinguish it from list/search siblings such as search_datasets and recent_datasets, even though it does not name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'by its id or slug' gives a clear condition for when this tool is appropriate: when the agent already has a dataset identifier. However, it does not explicitly point to alternatives like search_datasets for cases where the identifier is unknown, so some exclusionary guidance is missing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.